b. 11 August 1881 in Liverpool, the son of Thomas and Elizabeth Jones Lloyd. The family came from a strong nonconformist tradition in Denbighshire, and Lloyd inherited a deep love for rural Wales and for Welsh culture. He was educated at Liverpool College and at the University of Liverpool where he studied architecture in the university's Architecture School. From 1907 to 1912, he was an assistant to Sir Raymond Unwin in the Hampstead Garden Suburb. He was appointed, in 1913, the consulting architect to the Welsh Town Planning and Housing Trust and he designed a number of new villages in England and Wales, e.g. in Fishguard, Llanidloes, Menai Bridge and Llangefni as well as St. Francis Church in Barry, St. Margaret, Wrexham, the Students’ Union, Cardiff, and housing for the Forestry Commission and Coal Board. He was one of the founders of the Town Planning Institute in 1914. He entered into partnership with Alex J. Gordon in 1948. He became a member of the Cambrian Archaeological Association in 1919 and he was chairman of its general committee 1951-54 and President in 1958-59. With his wife, Ethel Roberts, M.A. (they m. in 1914), he attended the Association's annual meetings, regularly. He was one of the founders of the Council for the Protection of Rural Wales in 1929 and served as chairman from 1947 to 1959. He was president of the South Wales Institute of Architects, 1929-31, and president of the National Housing and Town Planning Council, 1933-35. He served on the Minister of Health's Advisory Committee on Town and Country Planning, 1933-40; on Lord Reith's Consultative Panel on Reconstruction, 1941-42; on the Central Advisory Committee on Education (Wales), 1945-48; on the Royal Commission on Ancient Monuments (Wales), 1949-60; and, on the Postmaster General's Welsh Stamp Committee, 1957-58.

He published a number of books, Planning in town and country (1935); Brighter Welsh villages and how we can achieve them (1931); and, with Herbert Jackson, South Wales outline plan (1947), as well as a number of articles.

He was a J.P. and chairman of the Discharge of Prisoners Aid Society in Cardiff. He was awarded an hon. LL.D. by the University of Wales in 1950; elected F.S.A. in 1953; and appointed O.B.E. in 1958. His home was at Hafod Lwyd, Heol-wen, Rhiwbina, Glam., but he died on his holidays at Torquay on 19 June 1960.